Abstract This application requests renewal of the current grant supporting the Biostatistics Research Center (BRC) for the Teen-LABS (TL) consortium. This multicenter, prospective, observational study seeks to evaluate the risks and benefits of bariatric surgery in 242 consecutively recruited adolescents undergoing bariatric surgery at the participating five clinical centers. By the end of the current funding period (August 2016), most study subjects will have completed 5 years of follow-up. With a funding renewal, the BRC continue to lead the data collection and management and statistical analysis operations for the TL consortium. A renewal of funding will provide an opportunity to collect and examine long-term outcomes of Roux-en-Y gastric bypass and sleeve gastrectomy, the most commonly used operations today. Collection of additional longitudinal measures from years 6 to10 will importantly document durability of weight loss, comorbidity resolution, quality of life, micronutrient status, and will identify long-term adverse events. Continued collection of biospecimens will continue to drive new discovery by investigators utilizing the ancillary studies mechanism. Addition of new measures to study bone health, cognitive function, and behavioral patterns will further enhance the value of an extension of the study.